The research in this proposal is intended to determine how ongoing stressful experiences are causally related to the occurrence of asthmatic symptomatology in the daily lives of asthma patients. The study is based on the proposition that psychological stress causes an increase in asthmatic symptoms. Two measures of stress will be employed: 1) a measure of daily stressful thoughts, based on the cognitive model of stress (cf. Lazarus, 1975) (Sandler, Note 2); 2) a measure of daily hassles (developed by Kanner, Coyne, Schaefer & Lazarus, 1981) based on the life events model of stress. Asthmatic symptomatology is measured by the Asthma Symptom Checklist (Kinsman, O'Banion, Resnikof, Luparello, & Spector, 1973). Subjects will be obtained from a list of patients who have been seen for asthma at the Student Health Center at Arizona State University. They will complete all three questionnaires on a daily basis for nine weeks, and will have a measure of pulmonary function (FEV1) taken once a week. Measures of stress and symtomatology will be analyzed using the cross-correlation function (CCF) (McCleary & Hay, 1980), a form of concomitant time series analysis (Cook & Campbell, 1979). This approach allows us to determine the extent to which the variables are related within individuals and to what degree each variable predicts ratings of physical symptoms. The CCF allows the researcher to determine both the strength and the direction of a relationship making it possible to draw inferences regarding causality between the stress experience and level of symptomatology.